Charging device for truck mixers



Dec. 9, 194i. c. F. BALL 2,265,751

CHARGING DEVICE FOR TRUCK MIXERS Filed Dec. 6, 1939 4 Sheets-Sheet 1' Charles E'Ball INVENIOR.

ATTORNEY.

Dec. 9, 1941. c. F. BALL 2,265,751

' CHARGING DEVICE FOR mucx MIXERS Filed Dec. 6, 1939 4 Sheets-Sheet 2 FIG. 2. 64 e7 INVENT OR.

ATTORNEY.

D. 9, 1941 c F. BALL 2,265,751

CHARGING DEVICE FOR TRUCK MIXERS Fild Dec. 6, 1939 4 Sheets-Sheet 4 Charles EBall INYEN'I'OR.

ATTORNEY.

Patented Dec. 9, 1941 UNE'EE s CHARGING DEVICE FOR TERENCE ES Charles F. Ball, Wauwatosa, Win, asmgnor to C Belt iliompany, Milwaukee, Wis a can mention oi Wisconsin Application December 6, 1939, Serial No. 307,784.

19 claims. (or. 259- 164) I'his invention relates to concrete mixers and particularly truck, mixers in which a rotatable .mixing drum is mounted on a'motor truck for transportation purposes. In such mixers, it is customary to arrange the axis of the drum longitudinally of the truck with the forward end ad- Jacent the cab, closed, and the opposite end, at the rear of the truck, provided with an opening for discharging the mixed concrete. This opening has also been used for charging the drum,

spiral blades being arranged within the drum for moving material toward or away from said opening depending upon the direction of rotation of the drum.

It is an object of the present invention to provide new and improved means for charging a.

drum of the type referred to, whereby a large percentage of the drums volume may be filled with concrete material and the time requiredfor charging and discharging reduced to a minimum.

A further object of the invention is to provide a charging hopper for mixer drums, which may be moved into co-operating position with an end discharge opening, and when in this position maintained under pressure in such sealed-tight relationship with the drum that the latter may be rotated, not only in the mixing direction, but also in a discharge direction and material worked back into the hopper by the drum blades, from whence it may return to the drum under gravity action. Accordingly it is-possible not only to ob- Figure 2 is a central longitudinal section of the deviceshown in Figure 1;

Figure 3 is a rear elevation of the device shown in Figure 2; 1

Figure 4 is a transverse section taken on the line ii-4 of Figure 2;

Figure 5 is a detailed section of the seal taken on the-line 5--5 of Figure 3;

Figure 6 is a transverse section through the hopper taken on the line 6- -5 of Figure 2;

Figure 7 is a section similar to Figure 2 show ing a modified form of the invention;

Figure 8 is a section taken on line 88'of Figure 7; and a Figure 9 is an enlarged central section taken on the line 8-9 of Figure 8.

Referring to Fig. 1 of the drawings, the nutated on an inclined axis with the rear or distain end to end mixing action during rotation opposite to that of normal mixing, 'but also to observe and sample through the hopper, prior to discharge of the drum contents, the mixed concrete which has been moved into the hopper as aforesaid.

Another object of the invention is to provide a charging device of rugged construction mounted in such a manner with respect to the frame of the truck mixer that road shocks may be ab-' sorbed and a minimal of wear result between the charging device andits seat on the mixer drum.

'With the above objects in view, the invention resides in the novel construction, combination and arrangement of parts substantially as here inafter described and more particularly defined in the appended claims.

Two embodiments of the invention are shown in the accompanying drawings in which like numbers are used to designate like parts in all views, and in which Figure 1 is a side elevation of the rear portion of a truck mixer-showing an embodiment of the invention;

charge end higher than the forward end. While the present invention is particularly useful with drums having a high end discharged as shown in said patent, it is by no means limited to such applications, but may be utilized to obtain greatly improved results with drums which are rotated on a horizontal axis.

The rear portion of drum H is frusto-conical, providing an open end I4 to whichis secured a flange or bearing ring l5, arranged axially of the drum and co-operating with rollers l6 mounted on frame l2. Spiral blades l'l within the drum are designed to move concrete from the opening toward the closed end when the drum is rotated in one direction, and upon reversal ofthe direction of rotation, to move concrete from the drum through the opening. The diameter of the opening I may be of substantial size, a suitable diameter being about thirty-four inches for a mixer drum having a capacity of approximately four cubic yards of material, such an opening insuring rapid charging and discharging. Surrounding the sides and bottom of the drum opening is a chute I! for directing concrete dischargedfrom the drum, said chute being disposed beneath the opening so as not to interfere with the charging device hereinafter described.

'with the basic supporting tube 2|.

1 ".which is slotted Extending-along the-axis or the drum, through the opening I4 is a tubular member or shaft 2| which is supported by and rigidly connected to the interior of the drum by means of an annular;

against the flange I5 of the drum and forms a seal 28. At the rearward end of the sleeve 24 a radial thrust bearing 29 is provided which is retained .by a cap 30 which may be used as water supply fitting, and which is attached to a housing 3| mounted on a thirdv tubular member or a rod 58 operatively connected to a hand wheel I 59 located in a convenient position for manual operation. By means of the linkage described, rotation of the hand wheel causes the hopper and the annular member 26 to move in an axial direction with respect to the drum, such motion being along the line of tubular member 2| upon which the feeding device is mounted. To equalize the pressure on both sides of the hopper and to absorb road shocks and strains caused by tilting of the frame, each link'50 may be made in two parts with one telescoping the other. This arrangement is best illustrated in Figure 8, which, although it relates to a modified form of the invention, discloses a section through the same spring assembly as is employed in the form shown in Figure 1. The portion of link 50 which sleeve 32, sleeve 32 being arranged concentrically of sleeve 24 and tube 2|. By means of bearing 29, thrust may be transferred from sleeve 32 invwardly to sleeve 24 along the axis of tube 2|. Similarly thrust forlmoving sleeve 24 outwardly of the drum may be taken through bearing 29 .and nut 33 threaded to the end of sleeve 24. For locking the bearing in its cage, the outer surface of nut 33 is splined and a lock washer 34 is inserted between the bearing and the nut.

A hopper or 'feeding device35 is rigidly associated with sleeve 32, said sleeve extending transversely of the hopper slightly below the.

middle thereof. As clearly shown on Figures 2' and'3, the three concentric tubular members 2|, 24 and 32 extend through the hopper with the bearing 29 disposed behind the rear wall of the of symmetrical plates 31 and 36 meeting to form a fairly sharp forward edge and flared out at the bottom to merge with the wall of the hopper.

Plates 36, 31 and 33, best shown in Figure 6,

afford a stream-lined deflector for material through the hopper andprevent material from collecting around the tubular members.

is pinned to the arm 5| terminates in a tubular housing 60 enclosing a coil spring 6| interposed between a flanged portion or seat 62 (at the forward end of the portion of link 50 attached to the trunnion) and a cap 63 threaded on the end of the housing. Consequently when force is applied to' draw the hopper toward the drum, pressure is exerted from cap 62 through the spring 6| to seat 62, which pulls the hopper toward the left on the drawings. Conversely when the hopper is moved from the drum, the shoulder at the bottom of the housing 60 abuts against the seat 62 and moves the link 50 to the right.

I The upper portion of the hopper is held against torque by a parallel link mechanism which ineludes asleeve 64 mounted on shaft 52, pendant arms 65 carried near the opposite ends of said sleeve and a U-shaped rod 66, which is pinned to the lower extremities of arms 65 and jour- The inner portion of hopper 3,5,, which presents Y a face radial of the drum axis is provided-with a perimetric seal 46 to permit relative rotation between the annular memberil and the hopper Figure 5, a pair of flexible members 4| are assembled to provide an annular channel, the sides of which extend radially from the. hopper.

Members 4| are retai'riedon the end of thehopper by a'split ring 42 and straddle a tapered or spreading ring 43 extending inwardly from annular member 26. Grease fittings, such-as 44,

communicating with the space at the bottom of the-annular channel may be arranged in the ring 43 to supply lubricant forthe seal 40.

nion is pivoted in one end of' a link 50, the oppositeend of which is pinned to an arm 6| secured to a transv se shaft i2 pivoted at the top of frame l2. t 62 is actuated by an arm by a crank 66 he ed to a worm wheel 56. The worm wheel is driven by a worm 51 mounted on Each trund 18888 a pin 64 carried nalled on bearings 61 mounted "on the hopper.--

This mechanism will resist torque and at the samev time enable the hopper to be moved on the tubular member 2 I.

As previously stated, member 2| may be utilized as a water conduit inwhich caseit is tubu-, vlar with the inner end extending well into the drum where it may be protected by a yneot valve means, well known in the art, 'for pro-- venting concrete from working back into the pipe. At the outer end of the pipe, bolted to the bearing housing 3|, is a cap 3|l-to which is connected a flexible hose l2 communicating with sleeve 24 and tube 2| as at 15 to permit relative rotation and prevent concrete from entering the sleeves, seal 15 also acting as a wiper to remove concrete collecting: on the tube 2 The operation of the device is as follows:

When it is desired to charge the'drum, the I hand wheel 59 is turned to swing shaft 62 in a clockwise direction as shown in Fig. 1. The force is transmitted through the back of the hopper .and draws the sleeve 32 and the hopper toward the drum. This force is likewise transmitted through the bearing 29 to move the sleeve 24 toward the left on the pipe 2|. Eventually upon suiilcient translation of-sleeve 24 and spider 28,

annular member 26 will be drawn into tight contact withthe end of the drum. Duringsuch translation the hopper will be moved a similarand the pressure at the seal 28 .is sufllcient to cause the annular member '26 to rotate with the drum, said member running in the seal M between it and the hopper 35 which remains stationary. These seals are so eflective that material may be charged well abovethe lower edge of seal 28 and consequently the drum may be charged while it is rotated to cause a shrinkage of the mix and enable larger volumes to be charged. i

It will be observed that the spiral blades IT which extend nearly to the end of the drum form tortuous passages through which material is moved, the direction of movement axially of the drum depending upon the direction of rotation. During rotation in a discharge direction, each blade will at one time in the course of its movement form a chute sloping toward the opening It, while at the same time, the other blade, which has progressed beyond this position, forms part of-a' passage leading back into the drum. Hopper 35, by providing a space communicating with these two passages permits the concrete to be moved into the hopper and thence back to the drum, the bottom of the hopper and the bottom. oi the cone portion of the drum forming an inclined surface sloping downwardly toward the closed oriorward end of the drum. By providing a drum which rotates on an inclined axis, this back and forth movement is still further improved. Moreover, with an inclined drum end charging is facilitated since the bottom of the charging passage is more nearly vertical than with a machine. rotated on a horizontal aris.

To discharge the drum, the hopper and associated members are moved to the dotted line at the right, shown on Figure 2, by rotating the hand wheel 59 in the appropriate direction. The mixed concrete is then worked out through the opening i lby the blades H and falls into the chute i8.

In Figures 7, 3 and 9 a modified form of the invention is shown in which the links so associated with the actuating mechanism are not connected to trunnions carried by the hopper 35, but are extended and house bearings 8! at the ends of a transverse horizontal bar 32 disposed behind the hopper. Midway of bar 82 is an aper ture which contains the bearing assembly, shown in detail in Figure 9, in most respects similar to thatin the formfirst described, but=difierlng essentially in the fact that thehousing fit is not attached to the hopper, but is spaced therefrom means employed to effect which are th same as in the form first described. Continuously, pressure is applied through the spring 83 to urge the hopper toward the plate to maintain a seal M against which the plate may run while the hopper remains stationary.

With either embodiment of the invention, the

objects originally stated may be obtained. Neither embodiment is intended to limit the scope of the invention, which is to be limited solely by the following claims.

I claim:

1. In combination with a rotatable mixing drum having an opening in one end thereof, a

shaft arranged axially of said drum and said opening, a charging device slidably mounted on said shaft, but held against rotation therewith, a pressure plate disposed between said opening and said charging device, means for moving said pressure plate and charging device into cooperative position ior charging said drum, said pressure plate being held under pressure against said drum to cause it to rotate therewith, and sealing means between said pressure plate and said charging device.

2. In combination} with a rotatable mixing drum having anopening in one end thereof, a shaft arranged axially of said drum and said opening, an annular member slidably mounted on said shaft having a portion disposed to enclose said opening, a hopper carried by said annular member and co-operating therewith for charging said drum, a seal between. said annular member by aspring 83 which is seated against the outer end of sleeve trassociated with the hopper. The bearing assembly is linked to the transverse member 82 by pins 86 extending in vertical alignment from the bearing housing 3! through apertures in the transverse member. A pair of lugs 85 attached to the back of the hopper form keepers limiting rotation-oi the housing is by straddling the outer portion of 'pin 34 on'the upper side or the housing. Slight clearance is provided between the member 82 and the hearing housing in order that member 82 may pivot on the pins 8Q. a

A somewhat modified form of seal 3% is also employed between the pressure plate 2% and the hopper, since under the action of spring as the hopper is forced axially of the drum against the pressure plate. To facilitate this action, a radially extending flange 85 is' formed on the end of the hopper adjacent the pressure plate, and the pressure plate is turned inwardly of the hopper so as to provide a radial face 81 parallel to the flange 85 and spaced 2. short distance on the drum side thereof. Another flange 88 extends and said hopper and means for applying pressure to seat said annular member fixedly against said drum and to maintain said hopper stationary during rotation of said annular member with said 3. In combination with a rotatable mixing drum having an opening in one end thereof, a shatt arranged axially of said drum opening, a flrst'tubular member slidably mounted on said first shaft, a pressure plate carried by said tubular member and arranged to seal said opening, a second tubular member journalled on said first tubular member, a hopper mounted on said second tubular member, a running seal between said hopper and pressure plate and means for moving said pressure plate and hopper axially of said shaft into charging position and exerting 7 pressure thereon, whereby said pressure plate may be held under pressure to rotate with said drum while said hopper is being held stationary and said pressure plate runs in said seal.

4. In combination a rotatable mixing drum having an opening. at one. end thereof, a

tubular member mounted in said drum and extending axially therefrom, a hopper slidably mounted on said tubular member but spaced axially from said drum, an intermediate member rotatably mounted on said tubular member con- ,fining the space between said drum and said hopper, a bearing between said hopper and said intermediate member and means associated with said hopper for retaining said bearing and for exerting pressure through said bearing to cause said intermediate member to move with said hopper toward and away from said drum.

6. In combination with a rotatable mixing drum having an opening at one end thereof, a shaft arranged axially of said drum, a charging hopper slidably mounted on said shaft and a deflector disposed within said hopper for directing material around said shaft.-

7. A charging device for concrete mixers comprising a shaft arranged axially and exteriorly of one end of the mixer drum, a hopper slidably mounted on said shaft, trunnions extending transversely of said shaft at opposite sides of said hopper and operatively connected to said hopper to move it into and out of charging position, and actuating mechanism including compressible links associated with each trunnion for equalizin the presure applied on the trunnions.

8. In a mixing machine which has an openwith the hopper opening, said annulus beingend, rotatable drum and a shaft'extending-axially thereof, a charging device comprising a tubular member slidably mounted on said shaft, a spider and annular plate mounted on said tubular member, a second tubular member mounted on said first tubular member, a hopper mounted on said second tubular member and a bearing-disposed between said first and second tubular members rearwardly and outside of said hopper.

9. In a machine for mixing concrete, a drum mounted for rotation on a ilxed axis, one end of said drum having an opening for materials and the interior of the drum being provided with agitation-inducing blades terminating at the opening and 'disposed'to produce movement of the material toward said opening during rotation of thedru'm in one direction; a member mounted exteriorly of the drum and movable to and from said opening, said member when in position contiguous to the opening providing a zone beyond theopening for receiving without discharge material worked to said opening by blade action. during rotation in said direction, and from which zon said material will be constantly returned by gravity to the drum thereby producing an endwise mixing action without discharge of the material during rotation in said direction; and means for moving said member away from the opening to cause discharge of the mixture from the latter.

10. In a machine for mixing concrete-a drum mounted for rotation on a fixed axis, one end of said drum having an opening for materials and the interior of the drum being provided with agitation-indi cing blades defining passages leading to said opening: a hopper for charging materials into the drum, movable longitudinally thereof to and from a charging position axially spaced from. the drum opening; an annular member, intermediate the drum and h pper and movable with the latter to and from engagement with the end portion of the drum, said member and hopper in the charging position providing a space beyond the drum opening into which the materials agitation and from which space they may be constantly returned to the drumby other of said passages; and means for moving said hopper and member to disengage the latter from the drum, whereby the mixture may be discharged through said opening. g

11. In a machine formixing concrete, a drum mounted for rotation on an inclined axis, the upper end of said drum havinga full diameter opening for materials and the interior of the drum being provided with agitation-inducing blades disposed to produce movement of the material to said opening during rotation of the drum in one direction; a hopper having an opening of lesser diameter than-said drum opening for char g materials therethrough into the drum, sai hopper being movable longitudinally thereof to and from a charging position axially spaced from the drum opening; an frusto-c'onical annulus having its smaller end communicating movable withthe hopper to bring its larger end into communication with said drum opening in the charging position of the hopper, in which position said annulus provides a zone beyond the drum. opening into which the material may be moved by said blade action and from which zone the material will be constantly returned to the drum by gravity action; and means for moving said hopper and annulus away from said charghopper being mounted for rectilinear'movements I toward and from the drum opening; an annular member rotatable relative to said hopper and rectilinearly movable therewith, said memberextending from said hopper opening toward the drum opening; and means for moving said hopper and member. to engage the latter with the drum to constitute an extension thereof and to produce rotation of said member.

13. In a machine for mixing concrete, a rotatable mixing drum having an opening in one end thereof for charging and discharging materials;

a charging hopper having a discharge opening of smaller diameter than said drum opening disposed complemental-to and axiallyspaced from 5 said drum. opening, said hopper being mounted seal between said member and hopper.

may be received from said drumpassages during 14. In combination with a rotatable mixing drum having an opening in one end thereof and a shaft integral with said drum extending axi-' ally and outwardly from said opening a charging device slidablymounted on said shaft, a substantially frusto-conical pressure .plate disposed be tween said drum and said charging device with its larger end arranged to enclose said drum. opening, said'plate also being slidably mounted on said shaft, but being free to rotatewith respect to said charging device, and means for an,-

said drum in order that it may rotate therewith.

15. In a truck mixer having a frame and an open-end, rotatable mixing drum mounted thereon, a shaft arranged axially of said drum, a sleeve slidably mounted on said shaft and carrying a substantially frusto-conical plate with its larger end arranged to enclose said drum opening, a hopper constantly maintained in upright position journalled on said sleeve with its lower end enclosing the smaller end of said plate, an annular seal between said plate and said hopper, a bearing between said hopper and said sleeve, and actuating mechanism mounted on said frame for moving said hopper and said plate into charging position and for maintaining said plate in pressural engagement with said drum so that it may rotate therewith.

16. In combination with a rotatable-mixin drum having a charging opening in one end thereof; a charging duct arranged to be aligned with said opening, but spaced axially therefrom; a rotatable, material-conducting, member disposed between said duct and said drum and arranged to enclose said drum opening, means for applying pressure to maintain said duct inproper charging position relative to said member and for accurately seating said member with respect to said drum, said member being movable with said duct into and out of charging position and being rotatable with said drum when in pressural contact therewith.

17. In combination with a rotatable mixing drum having an opening at one end, a shaft axially mounted in; said drum and extending exteriorly thereof, a charging hopper arranged to charge material through said opening and having an internal sleeve slidably mounted on said shaft, and'means connecting the underside of said sleeve with the bottom of said hopper, said means directing material away from the space between said sleeve and said hopper.

18. A charging device for rotatable mixing drums provided with an end charging opening, said device comprising a substantially frustoconical or dished annulus mounted adjacent said charging opening for rotation with the drum, 2. non-rotatable charging duct supported adjacent said annulus and having its discharge end disposed to pass material through the opening in said annulus, and sealing means between said duct and annulus.

19. In combination with a rotatable mixing drum having an end opening for charging and discharging materials and a shaft integral with said drum extending axially and outwardly from said opening, a charging hopper mounted on said shaft, a thrust bearing disposed between said shaft and said hopperrearwardly of said hopper, means exerting pressure through said bearing to urge said hopper toward said drum, means for retaining said hopper in upright position during drum rotation and a seal disposed between said hopper and said drum.

' CHARLES F. BALL. 

